What is the estimated carrier and affected rate for CEA in the Toller?
Researchers ESTIMATED the carrier rate to be approximately 5% in a very small sample of unrelated Tollers. This was done by testing 22 NSDTRs selected at random from the blood samples held at OptiGen, but none sharing parents, owner, or kennel name and coming from the US, Canada and Europe. This is somewhat a rough estimate, but adequate to get a sense of carrier frequency, that is, lower than prcd-PRA but high enough to indicate a genetic problem of significance. Within a particular pedigree known to pass CEA, carrier rate can reach 25 to 50% in some breedings. There really is no such thing as a reliable estimate of breed wide incidence because pedigrees occur in clusters. The frequency of carrier rate will vary: it can be zero or can be as high as 50% within a line of carriers. So although the carrier rate is estimated to be low overall across the breed, it can segregate into certain lines. As far as affected rate, the rule of thumb is that the affected rate is 1/10th the carrier rat
